LOS ANGELES –Police said a witness has come forward to describe the car used by the gunman in the fatal shooting of a 20-year-old college student on a busy Southern California freeway.

Michael Livingston was shot in the head Tuesday afternoon while he was driving on the northbound lanes of the 110 Freeway. His car slammed into the center divider and he died at the scene.

Investigators said no witnesses came forward immediately. Livingston’s parents made a public plea for witnesses to call police and even stood by the freeway on Thursday to hand out photos of their son.

Finally, after two days without a lead, a witness called detectives to describe the getaway vehicle — a gray 1996 Lincoln towncar with four doors, tinted windows and spoke rims. The northbound car exited at Florence Avenue.

Police say that’s a good start, but they need more information. Anyone with more information is asked to call (877) 529-3855.